Coaxial cables are present in a wide variety of electronic devices. Frequently, coaxial cables carry radio frequency (RF) signals from RF modules to antennas in an electronic device.
Changes in the physical routing of coaxial cabling along a backplane, such as a printed circuit board, can affect the electrical characteristics, such as impedance, of the coaxial cabling or adjacent components or both. Maintaining an intended arrangement of the physical routing of coaxial cabling during and after assembly produces an electronic device which performs as engineered.
Shrinking devices and use of surface mount technology has rendered routing coaxial cable runs within electronic devices more critical. Many small form factor devices such as e-book readers, cellular telephones, portable media players, laptops, netbooks, and the like, utilize coaxial cables.
However, the low profile and volumetric confines of these small form factor devices, combined with the small diameters of coaxial cable used, makes establishing coaxial cable routing during assembly a challenge.
In addition to maintaining the physical routing of the coaxial cabling, proper grounding of the coaxial cable poses further challenges in electronic devices. Improper, erratic, or incomplete grounding of coaxial cable can result in electromagnetic interference between components in the device, adversely affecting performance.
Effectively grounding coaxial cable during assembly can be particularly difficult given the small size of surface mount devices and the small diameter of coaxial cable often used. For example, grounding by soldering a shield of the coaxial cable to a printed circuit board is difficult, expensive in time and labor, and likely to damage the coaxial cable. Desoldering or cutting is required during subsequent removal of the coaxial cable.
Thus, surface mount electronic devices which use coaxial cabling pose special challenges in physical routing and grounding during assembly and repair.